Nucleation and growth theory in zeolite synthesis

1998 ◽  
Vol 21 (4-6) ◽  
pp. 333-336 ◽  
Author(s):  
C.G. Pope
Keyword(s):  
Nucleation And Growth ◽  
Growth Theory ◽  
Zeolite Synthesis

scholarly journals Non-Isothermal Crystallisation Kinetics of Polypropylene at High Cooling Rates and Comparison to the Continuous Two-Domain pvT Model

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1515
Author(s):  
Jonathan Alms ◽  
Christian Hopmann ◽  
Jian Wang ◽  
Tobias Hohlweck
Keyword(s):  
Injection Moulding ◽  
Polymer Processing ◽  
Nucleation And Growth ◽  
Growth Theory ◽  
Crystallisation Kinetics ◽  
Cooling Rates ◽  
Dsc Measurements ◽  
Wide Range ◽  
High Cooling Rates ◽  
Kinetics Of

The modelling of the correlation between pressure, specific volume and temperature (pvT) of polymers is highly important for applications in the polymer processing of semi-crystalline thermoplastics, especially in injection moulding. In injection moulding, the polymer experiences a wide range of cooling rates, for example, 60 °C/min near the centre of the part and up to 3000 °C/min near the mould walls. The cooling rate has a high influence on the pvT behaviour, as was shown in the continuous two-domain pvT model (CTD). This work examined the Hoffman–Lauritzen nucleation and growth theory used in the modified Hammami model for extremely high cooling rates (up to 300,000 °C/min) by means of Flash differential scanning calorimeter (DSC) measurements. The results were compared to those of the empirical continuous two-domain pvT model. It is shown that the Hammami model is not suitable to predict the crystallisation kinetics of polypropylene at cooling rates above 600 °C/min, but that the continuous two-domain pvT model is well able to predict crystallisation temperatures at high cooling rates.

The Stimulated Crystallization of Amorphous SiO2 Films on Si Substrates Induced By Laser and Thermal Treatments

1988 ◽  
Vol 116 ◽  
Author(s):  
Felix Edelman
Keyword(s):  
Incubation Time ◽  
Crystallization Process ◽  
Laser Flash ◽  
Nucleation And Growth ◽  
Point Of View ◽  
Growth Theory ◽  
Thermal Treatments ◽  
Kinetic Characteristics ◽  
Amorphous Sio2 ◽  
Si Substrates

AbstractThe transformation of amorphous to crystal (a-c) structure of Si02 layers, thermally grown on both (100) and (111) Si substrates, was carried out by CO2 laser, flash-lamp, and furnace heat: treatments. All the treatments resulted in S102 crystallization according to two different mechanisms: normal and self-sustained growth processes. The kinetic characteristics of the S102 crystallization process such as incubation time, rates of nucleation and growth, and the microstructure of the Si-Si02 interface were investigated and are discussed from the point of view of growth theory. The a-c transformation in Si3N4 and SixOyNz films on Si substrates is also discussed.

Prediction of Ferrite Transformation in Nb-Containing Microalloyed Steels during Continuous Cooling

2011 ◽  
Vol 189-193 ◽  
pp. 1137-1141
Author(s):  
Bing Yun ◽  
Jian Zhi Sun ◽  
Jian Lin Sun ◽  
Xiao Lei Dong
Keyword(s):  
Computer Simulation ◽  
Grain Size ◽  
Nucleation And Growth ◽  
Microalloyed Steels ◽  
Growth Theory ◽  
Transformation Behavior ◽  
Continuous Cooling ◽  
Ferrite Transformation ◽  
Ferrite Grain Size ◽  
Start Temperature

This paper considers for transformation behavior of Nb microalloyed steels, experiments had demonstrated the effect of Nb was obvious: lowered start temperature of ferrite transformation remarkably and forming more refined ferrite grain size. In this study, computer simulation of Nb-containing steels transformation during continuous cooling was carried out by adopting a classical nucleation and growth theory, the model was derived based on the theories and the experimental results, and the calculated start temperatures of ferrite transformation were compared with the results of experimental.

Shape control of inorganic nanoparticles from solution

Nanoscale ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 1237-1259 ◽  
Author(s):  
Zhaohui Wu ◽  
Shuanglei Yang ◽  
Wei Wu
Keyword(s):  
Shape Control ◽  
Nucleation And Growth ◽  
Inorganic Nanoparticles ◽  
Growth Theory

The controlled shapes of inorganic nanoparticles through diverse mechanisms in solution were discussed based on classical nucleation and growth theory.

scholarly journals Extraordinary Nanocrystalline Pb Whisker Growth from Bi-Mg-Pb Pools in Aluminum Alloy 6026 Moderated through Oriented Attachment

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1842
Author(s):  
Matic Jovičević-Klug ◽  
Patricia Jovičević-Klug ◽  
Tina Sever ◽  
Darja Feizpour ◽  
Bojan Podgornik
Keyword(s):  
Aluminum Alloy ◽  
Whisker Growth ◽  
Metallic Matrix ◽  
Nucleation And Growth ◽  
Oriented Attachment ◽  
Growth Theory ◽  
Sn Whiskers ◽  
Novel Concept ◽  
The Impact ◽  
Insight Into

The elucidation of spontaneous growth of metal whiskers from metal surfaces is still ongoing, with the mainstream research conducted on Sn whiskers. This work reports on the discovery of Pb whisker growth from Bi-Mg-Pb solid pools found in common machinable aluminum alloy. The whiskers and hillocks display unique morphologies and complex growth that have not been documented beforehand. In contrast to typical understanding of whisker growth, the presented Pb whiskers show a clear nanocrystalline induced growth mechanism, which is a novel concept. Furthermore, the investigated whiskers are also found to be completely composed of nanocrystals throughout their entire length. The performed research gives new insight into nucleation and growth of metal whiskers, which raises new theoretical questions and challenges current theories of spontaneous metal whisker growth. Additionally, this work provides the first microscopic confirmation of recrystallization growth theory of whiskers that relates to oriented attachment of nanocrystals formed within an amorphous metallic matrix. The impact of mechanical stress, generated through Bi oxidation within the pools, is theoretically discussed with relation to the observed whisker and hillock growth. The newly discovered nanocrystalline growth provides a new step towards understanding spontaneous metal whisker growth and possibility of developing nanostructures for potential usage in sensing and electronics applications.

scholarly journals Application of Crystal Growth Theory in Graphene CVD Nucleation and Growth

2014 ◽  
Vol 72 (3) ◽  
pp. 345 ◽  
Author(s):  
Lu Wang ◽  
Junfeng Gao ◽  
Feng Ding
Keyword(s):  
Crystal Growth ◽  
Nucleation And Growth ◽  
Growth Theory

Effects of Nd123/MgO Thin Film and MgO Single-crystal Seeds in Isothermal Solidification of YBaCuO/Ag

2000 ◽  
Vol 15 (8) ◽  
pp. 1742-1748 ◽  
Author(s):  
Chuanbing Cai ◽  
Hiroyuki Fujimoto
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Single Crystal ◽  
Isothermal Solidification ◽  
Nucleation And Growth ◽  
Domain Growth ◽  
Growth Theory ◽  
Stable Growth ◽  
Seeding Effects ◽  
Undercooling Degree

The seeding effects of (001) Nd123/MgO thin films and MgO single crystals were studied in isothermal solidification of YBa2Cu3Oy composite with the additions of 40 mol% Y2BaCuO5, 10 wt% Ag, and 0.5 wt% Pt. Seeding with the Nd123/MgO thin film resulted in single-domain growth of Y123 crystal with a stable growth along the “100”?direction, while seeding with MgO single crystal produced multidomain growth in which the dominant growth facet is rotated 45° about (100) plane of MgO. Multidomain growth in MgO seeded sample was suppressed by decreasing undercooling degree. The effects of undercooling degree and seed size on multidomain growth are discussed in view of classical nucleation and growth theory.

Application of Nucleation and Growth Theory to the Development of Industrial Products

1985 ◽  
Vol 57 ◽  
Author(s):  
John E. May
Keyword(s):  
Low Voltage ◽  
Nucleation And Growth ◽  
Heat Treatments ◽  
Growth Theory ◽  
Second Phase ◽  
Electrical Characteristics ◽  
Industrial Products

AbstractIn this paper we discuss some features of the microstructure of large-grainsized very low voltage varistors and the effects of heat treatments on the pre-breakover electrical characteristics. It is shown that a second phase precipitates in the bismuth-rich segregation phase and is thought responsible for the reduced device leakage properties.

Sign in / Sign up

Export Citation Format

Share Document